Summary of experimental details
| Experiment | Procedural summary | Primary finding |
|---|---|---|
| 1a | Pre-sample intra-PRh saline versus lidocaine; CMOR, tactile, and visual SOR; 1 h retention delay; n = 16 | Lidocaine selectively impairs visual SOR (Fig. 3A) |
| 1b | Pre-choice intra-PRh saline versus lidocaine; CMOR, tactile, and visual SOR; 1 h retention delay; n = 12 | Lidocaine impairs CMOR and visual SOR (Fig. 3B) |
| 2a | Pre-PE intra-PRh saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 13 | Lidocaine reverses facilitative effect of multimodal pre-exposure (Fig. 4A) |
| 2b | Post-PE intra-PRh saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 12 | Lidocaine reverses facilitative effect of multimodal pre-exposure (Fig. 4B) |
| 2c | Pre-sample intra-PRh saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 9 | Lidocaine reverses facilitative effect of multimodal pre-exposure (Fig. 4C) |
| 2d | Pre-choice intra-PRh saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 12 | Lidocaine reverses facilitative effect of multimodal pre-exposure (Fig. 4D) |
| 3 | Pre-sample intra-PRh saline versus lidocaine; PE/CMOR, PE versus no PE; 1 h retention delay; n = 10 | Lidocaine impairs performance only when rats have received multimodal pre-exposure (Fig. 5) |
| 4a | Pre-sample intra-PPC saline versus lidocaine; CMOR, tactile, and visual SOR; 1 h retention delay; n = 12 | Lidocaine impairs CMOR and tactile SOR (Fig. 6A) |
| 4b | Pre-choice intra-PPC saline versus lidocaine; CMOR, tactile, and visual SOR; 1 h retention delay; n = 10 | Lidocaine impairs CMOR and tactile SOR (Fig. 6B) |
| 5a | Pre-PE intra-PPC saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 11 | No effect of lidocaine (Fig. 7A) |
| 5b | Post-PE intra-PPC saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 9 | No effect of lidocaine (Fig. 7B) |
| 5c | Pre-sample intra-PPC saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 11 | No effect of lidocaine (Fig. 7C) |
| 5d | Pre-choice intra-PPC saline versus lidocaine; PE/CMOR, PE versus no PE; 3 h retention delay; n = 7 | No effect of lidocaine (Fig. 7D) |
| 6 | Rats exposed to 30 novel objects or yoked in empty Y-apparatus; simultaneous visual and tactile exploration possible; sacrifice 1 h later; brains processed for Fos expression; n = 16 (8 per condition) | Multimodal object exposure significantly increases Fos expression in PRh (Fig. 8 & 9) |
| 7 | Rats given multimodal exposure to 30 novel objects or yoked in empty Y-apparatus, followed by tactile exposure to same 30 objects or empty Y-apparatus 24 h later; sacrifice 1 h after second phase; brains processed for Fos expression; n = 16 (4 per condition) | Multimodal 'pre-exposure' followed by tactile 'sample' significantly increases Fos expression throughout PRh (Fig. 10) |
Order of experiments and number (n) of rats per experiment are shown. Different cohorts of rats were used for each experiment. Lidocaine experiments were within subject. PRh, perirhinal cortex; CMOR, crossmodal object recognition; SOR, spontaneous object recognition; PPC, posterior parietal cortex; PE, pre-exposure. Each yoked rat in Fos experiments spent the same amount of time in the empty Y-apparatus as a matched experimental rat that explored objects.